October is the month when gardeners need to be on the lookout for pests attacking their young leafy vegetables. It is prime time for two of the most annoying—and potentially devastating—insects in the fall garden.
When I teach, this is the time we break out the “Good Bug, Bad Bug” presentation. For adults, it just might be the gardening equivalent of “The Good, the Bad and the Ugly.” And October certainly has all three.
1. The Imported Cabbageworm
Picture this. Beautiful, graceful little cream-colored butterflies are fluttering and chasing each other around your cabbage and kale. It makes you sigh with peace. How lovely.
But wait.
Those innocent-looking little butterflies are imported cabbage white butterflies, and their offspring may be anything but lovely to your vegetable garden.The imported cabbageworm is the caterpillar stage of this butterfly. The caterpillars are no more than about an inch long and are velvety green, making them remarkably good at camouflaging themselves among cabbage, kale, broccoli and other leafy vegetables. They may be small, but don't let their size fool you. A few hungry caterpillars can demolish a young kale plant remarkably quickly.
Sometimes you look at your beautiful little seedling one day and think, “Look how well it's growing!” And the next morning…**Where did my kale go?**
How to Control Cabbageworms
There are a couple of ways to protect your garden from these hungry little caterpillars. The first is the simplest: mechanical control. In other words, go hunting. Look carefully for the caterpillars, especially on the undersides of leaves and along stems, and pick them off by hand. Their frass (insect poop) is a giveaway, too. It looks like dark little balls on the leaves.
Some children especially love picking up these caterpillars. There is something very satisfying about finding a caterpillar that has been munching away and sending it on its way. You can discard them in the trash or move them a good distance away from your vegetable garden. They aren't particularly speedy travelers, so distance works in your favor
The second option is Bt, or Bacillus thuringiensis. Bt is a naturally occurring bacterium used as a biological control for certain caterpillars. Follow the product label directions carefully when applying it to your vegetables. One important thing to remember: Bt washes off with water. So if it rains—or you wash it off while watering—you may need to reapply it according to the product directions. And don't forget that you aren't the only one looking for these caterpillars. Wasps are natural predators of cabbageworm caterpillars, so if you see wasps working around your garden, they may actually be helping you keep the cabbageworms under control.
Not every bug flying around your garden is out to get you!
2. Aphids
The second “bad bug” to watch for in October is the aphid. Aphids are tiny insects that feed on plant sap. They can attach themselves to many vegetables that are still hanging around from summer—especially eggplant leaves—and then move on to your fall crops. They are easy to overlook at first. They're tiny. They're often dark-colored. And they tend to start quietly on one plant. Then, before you know it, the whole bed seems to have joined the aphid convention. Aphids can be difficult to control once a population gets established, which is why I like to start with a simple mechanical method.
Wash Them Away
Use a strong stream of water to wash aphids off the leaves. You can also rub them off with your fingers. Although, fair warning: if you're not a fan of bug guts on your hands, wear gloves.
The goal isn't necessarily to kill every aphid you can find. The goal is to knock them off the plant and reduce the population enough to give your plants—and their natural predators—a fighting chance. And speaking of natural predators, that brings us to my favorite insect of the month.
3. Ladybugs—The Good Guys
Ladybugs, also called ladybird beetles, are one of my favorite garden allies. But before we get too excited about those cute little red beetles, we need to pause for a quick biology lesson. If you're looking for ladybugs in your garden, you need to know what they look like during all stages of their life cycle.
Ladybugs go through four stages:
Egg → Larva → Pupa → Adult
Everyone recognizes the adult ladybug. They're cute. They're colorful. They look like tiny little garden superheroes. But the larvae do not look anything like a ladybug. In fact, they can look downright frightening. They're elongated, often dark-colored, and covered with little spines or projections. If you don't know what you're looking at, you might assume you've discovered another nefarious garden pest. Quite the opposite.
Ladybug larvae are some of the most voracious aphid eaters in the garden. So before you squish that strange-looking little creature because you think it's a bad bug, take a closer look. You may have just found one of your best garden allies.
The Ladybug Rescue
I've seen this happen firsthand. I have seen times when I thought my kale patch was going to succumb to aphids. The aphids were multiplying, the plants were struggling, and things were looking rather grim. Then suddenly, a battalion of ladybug larvae invaded. And they went to work. The larvae began feeding on the aphids, and before long, the kale had a fighting chance again. It was quite remarkable.
This is one of my favorite things about gardening because it is a perfect example of how the garden can sometimes take care of itself—if we give it a chance.
Sometimes the best thing a gardener can do is recognize the good guys before reaching for a chemical pest solution.
Good Bug or Bad Bug?
October is a great month to practice your garden detective skills
Before you squish, spray or remove an insect, take a moment to figure out what you're actually looking at. Is it a cabbageworm? An aphid? A ladybug larvae? Or something else entirely?
Learning to recognize insects in their different life stages can make a huge difference in how you manage your garden. And it can turn a pest problem into a biology lesson. That's one reason I love teaching “Good Bug, Bad Bug.” The garden is full of surprises.
So this October, keep an eye on your leafy vegetables.
Look under the leaves. Look along the stems. Look closely.
And remember: Not every bug is a bad bug. Sometimes your garden's best defense is already there—you just have to know what you're looking at.
A GardenWise Thought
Before you reach for the spray bottle, stop and look closely. Your garden may already have its own little army working for you.
And sometimes, the hero doesn't look anything like a hero. 🐞
